I find myself wandering the Science corridor of my former school. I am somewhat disconcerted by the fact that nobody - none of my former teachers - recognise me, and I feel like a ghost. I wander the length of the building, and leave at the end of the English corridor.

When I get outside, I notice that a horrific cycling accident has occurred. I rush over, and find that an old friend of mine is attending the casualty. I immediately offer my help, and my friend suggests that I squat, and prop the cyclist's leg up on mine.

I do this without thinking, and then am somewhat disconcerted by the fact that the cyclist is bleeding profusely, and I have an exposed puncture wound on my thigh.

I express this concern to my friend, who rubbishes my fears. I, however, am not convinced, so I ask the cyclist, who is now standing up to leave.

"You don't have AIDS or Hepatitis or something like that, do you?" I ask.